1The Secret Inside the Tube
Have you ever wondered what is actually happening inside a glow stick when you snap it? It looks like a single liquid, but it is actually a clever science trick! Every glow stick contains a plastic outer tube filled with one chemical solution and a tiny, fragile glass vial floating inside it containing a second chemical called hydrogen peroxide. When you bend the plastic, you hear a 'crunch'—that is the glass vial breaking. This allows the two liquids to finally touch and mix, starting a chain reaction that produces the glow we love.
2What is Cold Light?
Most things that create light also create a lot of heat, like a burning candle or an old-fashioned lightbulb. This is because energy usually turns into thermal energy. However, glow sticks use a special process called chemiluminescence. In this chemical reaction, the energy released doesn't wiggle the atoms around to create heat; instead, it excites the atoms to release photons, which are tiny packets of light. Because no heat is created, scientists call this 'cold light.' This is very similar to how fireflies light up their tails using bioluminescence!
3Controlling the Glow with Science
You can actually use science to change how your glow stick works! Chemical reactions happen faster when it is warm and slower when it is cold. If you place a glow stick in a bowl of hot water, it will glow much brighter because the chemicals are bumping into each other faster, but it will also use up its energy and burn out quickly. If you put a glow stick in the freezer, the reaction slows down to a crawl. The light will be dimmer, but the glow can last for days! It is a great way to see chemistry in slow motion.
